Operation of Screw - type Water - cooled Chiller Units

Starting Steps of Screw - type Chiller Units

1. Check the power supply of the unit to ensure it is stable and up to standard.
2. Open the inlet/outlet valves of the chilled water.
3. Start the chilled water circulation pump and check whether the operating voltage and current are normal.
4. Open the inlet/outlet valves of the cooling water.
5. Start the cooling water circulation pump and check whether the operating voltage and current are normal.
6. Check whether the inlet/outlet pressure difference of the chilled water is normal.
7. Check whether the inlet/outlet pressure difference of the cooling water is normal.
8. Confirm that the chilled/cooling water systems are circulating normally.
9. Start the unit and wait until the unit operates stably.
10. Check the operating voltage and current of the unit.

    

11. Check the inlet/outlet water temperatures of the evaporator/condenser.
12. Check the refrigerant pressures of the evaporator/condenser.
13. Check whether the operating sound of the unit is normal.
14. Decide whether to start the cooling tower according to the inlet water temperature of the condenser.

Contents of Operation Records for Screw - type Chiller Units

1. Inlet/outlet water temperatures and pressures of the unit's evaporator/condenser.
2. Saturated temperatures/pressures of the unit's evaporator/condenser.
3. Exhaust temperature of the compressor.
4. Exhaust superheat and the control point of exhaust superheat.

   

5. Opening degree of the slide valve (opening degree of the electronic expansion valve).
6. Approach temperatures of the evaporator/condenser.
7. Operating voltage/current and coil temperature of the compressor.
8. Starting times and operating hours of the compressor.
9. Operating voltages and currents of the chilled water circulation pump/cooling water circulation pump.
10. Operating voltage and current of the cooling tower fan.

Stopping Steps of Screw - type Chiller Units

1. Confirm that the operating time of the unit this time is more than 30 minutes.
2. Stop the unit normally and wait until the unit stops completely.

   

3. Stop the cooling water circulation pump 5 - 10 minutes later.
4. Close the inlet/outlet valves of the cooling water.
5. Turn off the cooling tower fan.
6. Stop the chilled water circulation pump 10 - 30 minutes later.
7. Close the inlet/outlet valves of the chilled water.

Normal Operating Parameters of Screw - type Water - cooled Chiller Units

1. The setting range of the control current on the unit's control panel: 40 - 100%.
2. Set point of the chilled water outlet temperature: 5 - 10°C.
3. Supply temperature of the chilled water: 7 - 12°C; temperature difference for shutdown: 3 - 5°C; temperature difference for startup: 3 - 5°C.
4. Designed inlet/outlet water temperatures of the cooling water under working conditions: 23/32°C.
5. Operating pressure of the evaporator: 448 - 517 KPa.
6. Operating pressure of the condenser: 896 - 1585 KPa.
7. Pressure difference of the oil filter: greater than 30 KPa.
8. Approach temperature of the refrigerant in the evaporator: < 3°C.
9. Approach temperature of the refrigerant in the condenser: < 3°C.
10. Control point for high - pressure protection of the condenser: 1861 KPa.